Amplitude Relations in Coupled Circuits

An historical survey of previous work on coupled circuits is made. There are formed, in general, in coupled circuits two waves in both primary and secondary circuits. The amplitude ratios of the longer two of these waves and of the shorter two of these waves are calculated. Neglecting resistance, the shorter waves are opposite in phase, the longer waves in phase. A simple experimental method for rapidly verifying the theoretical relations is described. The ratios of the amplitude of the longer to the shorter primary wave and of the longer to the shorter secondary wave are theoretically determined for both condenser excitation and inductance excitation. It is shown that at resonance the magnetic fluxes of corresponding long or corresponding short waves are equal numerically. It also appears that maximum secondary effect is not obtained for equal natural periods of the circuits. The extent to which wave meter close coupling affects accuracy of wave length determination is considered. An explanation of dissymmetry of resonance curves about the resonance point is also given. All relations deduced are graphically illustrated.